headerparser 0.4.0

格式

RFC822样式头是遵循 rfc 822和friends指定的电子邮件头：每个字段是 表单“Name: Value”，长值连续到多行 通过缩进多余的行（“折叠”）。空行标记 标题部分和消息正文的开头。

除了电子邮件之外，许多文本格式都使用这种基本语法， 包括但不限于：

• http请求和响应头
• usenet消息
• 大多数python打包元数据文件
• Debian打包控制文件
• META-INF/MANIFEST.MF在Java JAR中的文件
• YAML序列化格式的子集

-所有这些都是这个包可以解析的。

安装

只要使用pip（你有pip，对吧？）安装 headerparser及其依赖项：

pip install headerparser

示例

定义解析器：

>>> import headerparser
>>> parser = headerparser.HeaderParser()
>>> parser.add_field('Name', required=True)
>>> parser.add_field('Type', choices=['example', 'demonstration', 'prototype'], default='example')
>>> parser.add_field('Public', type=headerparser.BOOL, default=False)
>>> parser.add_field('Tag', multiple=True)
>>> parser.add_field('Data')

分析一些标题并检查结果：

>>> msg = parser.parse_string('''\
... Name: Sample Input
... Public: yes
... tag: doctest, examples,
...   whatever
... TAG: README
...
... Wait, why I am using a body instead of the "Data" field?
... ''')
>>> sorted(msg.keys())
['Name', 'Public', 'Tag', 'Type']
>>> msg['Name']
'Sample Input'
>>> msg['Public']
True
>>> msg['Tag']
['doctest, examples,\n  whatever', 'README']
>>> msg['TYPE']
'example'
>>> msg['Data']
Traceback (most recent call last):
    ...
KeyError: 'data'
>>> msg.body
'Wait, why I am using a body instead of the "Data" field?\n'

无法分析不符合您要求的邮件头：

>>> parser.parse_string('Type: demonstration')
Traceback (most recent call last):
    ...
headerparser.errors.MissingFieldError: Required header field 'Name' is not present
>>> parser.parse_string('Name: Bad type\nType: other')
Traceback (most recent call last):
    ...
headerparser.errors.InvalidChoiceError: 'other' is not a valid choice for 'Type'
>>> parser.parse_string('Name: unknown field\nField: Value')
Traceback (most recent call last):
    ...
headerparser.errors.UnknownFieldError: Unknown header field 'Field'

允许您甚至没有想到的字段：

>>> parser.add_additional()
>>> msg = parser.parse_string('Name: unknown field\nField: Value')
>>> msg['Field']
'Value'

只需将一些标题拆分为名称和值，然后再担心其有效性：

>>> for field in headerparser.scan_string('''\
... Name: Scanner Sample
... Unknown headers: no problem
... Unparsed-Boolean: yes
... CaSe-SeNsItIvE-rEsUlTs: true
... Whitespace around colons:optional
... Whitespace around colons  :  I already said it's optional.
...   That means you have the _option_ to use as much as you want!
...
... And there's a body, too, I guess.
... '''): print(field)
('Name', 'Scanner Sample')
('Unknown headers', 'no problem')
('Unparsed-Boolean', 'yes')
('CaSe-SeNsItIvE-rEsUlTs', 'true')
('Whitespace around colons', 'optional')
('Whitespace around colons', "I already said it's optional.\n  That means you have the _option_ to use as much as you want!")
(None, "And there's a body, too, I guess.\n")